Pack of 4 Ductsure Door Relief Vent Grille Aluminium DG-A 636631 Somta Series 510 - HSSE-V Spiral Flute Tap Metric (Standard) 🔹 Thread Size: BSW 7/16"🔹 731mm HSS CO Cobalt 1151-300 Adjustable Roller Limit Switch

Pack of 4 Ductsure Door Relief Vent Grille Aluminium DG A 636631 Somta Series 510 HSSE V Spiral Flute Tap Metric (Standard) 🔹 Thread Size: BSW 7 16"🔹 731mm HSS CO Cobalt 1151 300 Adjustable Roller Limit Switch 🔹 Thread Size: BSW 7 16"🔹 Thread Standard: British Standard Whitworth (BSW)🔹 Thread Tolerance Class: Class 2🔹 Flank Angle: 55°🔹 Tap Type: Spiral Flute Short Machine Tap🔹 Helix Angle: 35° Right Hand🔹 Cutting Direction: Right Hand🔹 Application: General Purpose Blind Hole Tapping🔹 Shank Standard: ISO 529🔹 Material: HSSE V3 (High Speed Steel)🔹 Hole Type: Blind Hole To know what size the insert should be it refers to the last two digits in the code SER 1212 K11 meaning a 11ER insert